Difference between revisions of "D2n kinematics"
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*; Minimal/no positron running?
*; Minimal/no positron running?
** Perhaps measure the positron background in HMS at 20 degree and compare with model?
** Perhaps measure the positron background in HMS at 20 degree and compare with model ?
Revision as of 13:40, 2 August 2020
Run Plan (updated when needed)
- Draft d2n Run Plan
- NOTE: The SHMS + HMS kinematic pairings are different that what we were planning when those tables were constructed. We are starting with HMS Kin C and SHMS Kin X.
Rough / High-level sketch of d2n kinematic settings
Reduced kinematics list to accommodate limited beam time (dropped 1/4 of kinematics)
--------- Beam Params ---------- E_beam = 10.4 GeV/c I_beam = 30 uA P_targ = 0.50 P_beam = 0.80
--------- HMS ---------- E' theta x Q2 W A 4.2 13.5 0.207 2.414 3.178 B 4.2 16.4 0.305 3.554 2.993 *C 4.0 20.0 0.418 5.018 2.806 [Starting here] -- Only setting compatible with SOLID Cherenkov small-angle test.
--------- SHMS ---------- E' theta x Q2 W *X 7.5 11.0 0.527 2.866 1.859 [Starting here] Y 6.4 14.5 0.565 4.240 2.036 Z 5.6 18.0 0.633 5.701 2.046
- Not shown is the 1-pass running (2--3'ish days)
- We should expect to have 6 weeks of beam
- Hall C will have priority over Hall A (if there are beam loading, machine stability issues)
- Rough priorities:
We plan to start at 5-pass with kinematics A and X (small angle)
- We will start at 5-pass with kinematics C and X (small angle on SHMS, large angle on HMS)
- This will allow the SOLID Cerenkov prototype folks to setup before beam and run their small-angle test on the HMS side.
- Then move to kin A and Z (high-Q2 SHMS, small angle HMS)
- Scheduling of Kin B, Y and 1-pass running would depend on how the Accel/target/virus behaves
More Detailed Plan for when beam is handed to us (as of Sunday, August 2)
NOTE: I'm sure this will get tweaked...
- Moller measurement will be done on first available day shift -- looks like Monday DAY at this point
- Sanity check beam positions, harp profiles and convince ourselves the tune is still good (no need for Carbon Hole study unless something is really strange) - Ion Chamber calibrations (if not done already)
- Reference cell filled with N2 @ 10 Atm - Carbon Optics
- If the target is still pumping up, or if there are any concerns about the 'real' beam polarization, then
- Reference cell runs: 2 beam-hours each (skip He3 for now) - N2 @ 10 Atm - H2 @ 10 Atm - Empty / Vacuum
- Then move into production running:
HMS Kin C, SHMS Kin X (Total time: 125 PAC hours, ~10 calendar days) - Flip IHWP every 4--8 hours - Ensure Charge Asym Feedback is running/working - Take NMR meas. every ~5 hours - Target: Transverse - Flip target spin at 36 hours - 3-4 calendar days in, switch target to Longitudinal - Target: Longitudinal - Flip IHWP at 1/2 way into each run block (~4 hours) - ~11 hours @ 0deg - ~11 hours @ 180deg - Switch back to Transverse - Target: Transverse - 3-4 calendar days until Kin C/X are done - Flip target spin at 36 hours in
- Reference cell runs - Complete N2, H2, empty ref cell runs not completed yet (may be used as fill after a target spin flip/rotation) - He3 @ 10 hours (2 beam-hours) -- Do this once at the end of this kinematic
- This should take roughly 10 calendar days. - We'll then move to 1-pass for 3 days, then back to 5-pass and follow the above prescription for the remaining Kin A/Z, Kin B/Y
- Optics are generally in good shape, but we will should take more for HMS kin B (4.2 GeV/C @ 16.4 deg)
- Analyze and get the new matrices in the analyzer
- Make sure we have empty target runs for all kinematics help disentangle beamline window contributions
- Nail down estimates for ref cell running (N2, H2, 3He, empty)
- Minimal/no positron running?
- Perhaps measure the positron background in HMS at 20 degree and compare with model as a sanity check?
1-pass running considerations
- Request pass change to 1-pass
- Controlled Access to install collimator (RadCon)
- Restore 1-pass beam to Hall
- Begin production running following A1n 1-pass notes 1-pass_calibration_for_A1n_(Jan_2020)
- 3He elastic and QE longitudinal Asymmetries (incl. pressure curve / ref cell running)
- HMS setting: 11.7 deg, -2.1483 GeV/c
- SHMS setting: 8.5 deg, -2.12860 GeV/c
- Polarized 3He Delta Transverse Asymmetry
- HMS setting: 11.7 deg, -1.75830 GeV/c (electron W=1.232)
- SHMS setting: 8.5 deg, -1.79736 GeV/c (electron W=1.232)
- Pol 3He Elastic Measurement (E12-06-121A)
- Details Coming Soon